1. Field of the Invention
The present invention relates generally to a spray head air atomizing assembly and more specifically to an air atomizing assembly to control the flow of atomizing air in a fluid spray or other delivery device such as an air sprayer for spraying paints, adhesives, coatings, and other semi-liquid materials. The invention also relates to a method and system of spraying or applying such materials by using the atomizing air or air stream as a vehicle for delivering catalyst, an agent, moisture or other component to the application fluid and of conditioning the application fluid.
2. Description of the Prior Art
Two common types of spray or delivery devices exist for spraying or delivering a fluid to a substrate. One such device is a so-called airless type sprayer or delivery device in which an application fluid is forced through one or more nozzle openings at high pressure. With this type of device, the fluid is atomized or disbursed into tiny droplets as a result of the pressurized fluid passing through the nozzle opening.
A second such device is an air or air atomized spray gun or delivery device in which the application fluid passes through a nozzle orifice, at pressures usually much lower than the pressures employed with airless spraying, in combination with atomizing air flowing through a plurality of air orifices surrounding the nozzle opening. The atomizing air functions to atomize or disperse the application fluid after its exit from the nozzle opening.
While many of the air atomizing assemblies of the prior art are generally acceptable when being used to atomize relatively low viscosity materials such as paint which , because of their physical characteristics, are broken up and atomized easily, the performance of such assemblies is limited and less than satisfactory when used to atomize high viscosity materials (in excess of about 3,000 centipoises) and materials which have a high surface tension such as epoxies, urethanes, polyureas and other adhesives. These high viscosity and high surface tension materials are difficult to atomize and thus tend to “string” a lot as the application material travels from the spray nozzle to the substrate.
Further, in prior art air atomizing sprayers or application systems, the atomizing air has been used primarily as a means to atomize or disperse the application fluid, with the introduction of secondary reaction components or other agents, catalysts and components being accomplished via other conventional means.
Accordingly, there is a need in the art for an improved air atomizing assembly, and more particularly a need for an air atomizing nozzle assembly which provides improved atomization of both conventional low viscosity materials such as paints as well as materials which have a relatively high viscosity and/or a high surface tension such as adhesives and the like. There is also need in the art for improved methods and systems of conditioning the application fluid and introducing and mixing secondary reaction components, agents and catalysts with the application fluid.